Browsing by Author "Corrigall, Anne"

Now showing 1 - 6 of 6
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    Characterisation of the flavin adenine dinucleotide binding region in Myxococcus xanthus protoporphyrinogen oxidase
    (2011) Boateng, Mavis O; Meissner, Peter; Corrigall, Anne
    This dissertation focuses on protoporphyrinogen oxidase (PPOX), the penultimate enzyme in the haem biosynthetic pathway. Partial defects in PPOX result in variegate porphyria, an autosomal dominant disorder. PPOX catalyzes the six electron oxidation of protoporphyrinogen IX to protoporphyrin IX, in the presence of flavin adenine dinucleotide (FAD) and oxygen. FAD is a cofactor, functioning as an intermediate electron acceptor in the catalytic function of PPOX. In this study the FAD binding region in Myxococcus xanthus PPOX was analysed by engineering and characterising a selection of relevant mutants.
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    Expression, purification and characterisation of protoporphyrinogen oxidases from diverse species
    (2000) Siziba, Kwanele Bennett; Meissner, Peter; Corrigall, Anne
    This work involved the characterisation of protoporphyrinogen oxidase (PPO), the penultimate enzyme in haem biosynthesis, from Bacillus subtilis, Myxococcus xanthus, and human. A defect in human PPO causes variegate porphyria, an autosomal dominant disorder characterised by skin photosensitivity and propensity towards acute neurovisceral crises. At the beginning of this project little information was available on the kinetic and biophysical properties of isolated PPOs due largely to difficulties associated with their purification from natural sources.
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    Mitochondrial targeting of wild-type and mutant human protoporphyrinogen oxidase (PPOX)
    (2003) Davids, Lester M; Meissner, Peter; Corrigall, Anne
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    Molecular characterisation of acute intermittent porphyria in South Africa
    (2014) Fortgens, Philip Hendrik; Meissner, Peter; Corrigall, Anne; Berman, Peter; Pillay, Tahir
    Acute intermittent porphyria belongs to a group of inherited disorders of haem metabolism. The object of this project is to characterise the mutations in the hydroxymethylbilane synthase (HMBS) gene in a cohort of South African patients. The elucidation of these mutations will facilitate an understanding of the molecular basis of AIP in South Africa, and provide a platform for the screening of family members of affected patients. Identification of latent carriers would allow for education with respect to precipitants and how best to avoid them, so as to minimise the risk of provoking an acute attack.
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    Molecular characterisation of erythropoietic protoporphyria in South Africa
    (2006) Parker, Michelle; Meissner, Peter; Corrigall, Anne; Hift, Richard
    Includes bibliographical references.
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    Studies on human protoporphyrinogen oxidase
    (2002) Maneli, Mbulelo H; Meissner, Peter; Corrigall, Anne
    This study examines the effects of various protoporphyrinogen oxidase mutations responsible for variegate porphyria, the role of the arginine-59 residue, and the glycines in the conserved flavin binding site, in catalysis and/or cofactor binding. Wild type recombinant human protoporphyrinogen oxidase and a selection of both naturally occurring and self-designed mutants were generated, expresses and purified. The self designed mutants included a conservative and two non-conservative arginine-59 replacements, and substitution of glycine residues at positions 9, 11, and 14 by alanine. The expression and purification for all protoporphyrinogen oxidases was optimised, enabling their purification to homogeneity by single step metal affinity chromatography.